Ignition distributors

ABSTRACT

A method of assembling an ignition distributor includes the steps of engaging an annular timing plate with an annular base plate. Mating surfaces on the two plates locate the timing plate for angular movement on the base plate when the two plates are engaged. A deforming tool is engaged with three ears or tags formed on the base plate, and the ears are deformed into contact with the surface of the timing plate remote from the base plate. The physical properties of the ears are such that when the deforming tool is removed, the inherent resilience of the ears causes the ears to flex away from the timing plate through a predetermined distance so that a predetermined clearance exists between the timing plate and the ears. The predetermined clearance permits a predetermined axial freedom between the timing plate and the base plate. In a modification the timing plate is provided with upstanding projections into engagement with which the ears are deformed, the ears then flexing away from the projections when the deforming tool is removed, so that the clearance is equal to the heights of the projections plus the mount by which the ears flex.

United States Patent Cooksey I 51 Aug. 29, 1972 [54] IGNITION DISTRIBUTORS [72] Inventor: William Harold Cooksey, Walsall,

Staffordshire,England [73] Assignee: Joseph Lucas (Industries) Limited,

Birmingham, England 22 Filed: Aug. 12, 1970 21 Appl. No.: 63,245

[30] Foreign Application Priority Data Oct. 13, 1969 Great Britain 50,182/69 [52] US. Cl. ..29/598, 200/19 R [51 Int. Cl. ..I102k 15/02 [58] Field of Search ..29/437, 438, 598; 200/19 R, 200/19'A,19 B, 19 L, 19 E, 19 DR, 19 DC,

19 M, 19 TS, 19 W6; 310/42 France ..200/ I9 Primary ExaminerRobert L. Spicer, Jr. AttorneyI-lol'man & Stern [5 7] ABSTRACT A method of assembling an ignition distributor includes the steps of engaging an annular timing plate with an annular base plate. Mating surfaces on the two plates locate the timing plate for angular movement on the base plate when the two plates are engaged. A deforming tool is engaged with three ears or tags formed on the base plate, and the ears are deformed into contact with the surface of the timing plate remote from the base plate. The physical properties of the ears are such that when the deforming tool is removed, the inherent resilience of the ears causes the ears to flex away from the timing plate through a predetermined distance so that a predetermined clearance exists between the timing plate and the ears.

The predetermined clearance permits a predetermined axial freedom between the timing plate and the base I plate. In a modification the timing plate is provided with upstanding projections into engagement with which the ears are deformed, the ears then flexing away from the projections when the deforming tool is removed, so that the clearance is equal to the heights of the projections plus the mount by which the ears flex.

4 Claims, 3 Drawing Figures PATENTED M1829 I972 V421, Wow/w mm FiGS.

INVENTOR ATTORNEYS This invention relates to a method of assembling ignition distributors of the kind including a base plate which is secured to the casing of the distributor, and a timing plate mounted for angular movement on the base plate, the timing plate carrying the contact breaker assembly of the distributor.

A method according to a first aspect of the invention includes the steps of engaging an annular timing plate with an annular base plate so that mating'surfaces on the two plates locate the timing plate for angular move ment on the base plate, engaging a deforming tool with three ears which are formed on a first plate of the pair of plates defined by the timing plate and the base plate, and deforming the three ears into contact with the surface of the second plate remote from the first plate, said ears being disposed on the first plate in such a manner that any one of the ears is on the opposite side of a diameter of the first plate from the remaining ears, and the physical properties of the ears being such that upon removal of the deforming tool the inherent resilience of the ears causes the ears to flex away from the surface of the second plate through a predetermined distance so that a predetermined clearance exists between the second plate and the ears thereby rendering the first and second plates capable of relative axial movement through said predetermined distance.

A method according to a second aspect of the invention includes the steps of engaging an annulartiming plate with an annular base plate so that mating surfaces on the two plates locate the timing plate for angular movement on the base plate, and three projections on a second plate of the pair of plates defined by the timing plate and the base plate project from the surface of the when the plate 14 is moved angularly with respect tosecond plate, remote from the first plate, said projections being disposed on the second plate in such a manner that any one of the projections is on the opposite side of the diameter of the same plate from the remaining projections, engaging a deforming tool with three ears which are formed on the first plate, deforming the three ears into engagement with the surfaces of the three projections respectively, the physical properties of the ears being such that when the deforming tool is removed, then the inherent resilience of the ears causes the ears to move away from the surfaces of the projections through a predetermined distance, removing the deforming tool to allow the ears to move away from the surfaces of the projections respectively through said predetermined distance, and then rotating the first and second plates relative to one another to displace the projections angularly from the three ears so that the first and second plates are capable of relative axial movement through a distance equal to the height of the three projections, plus said predetermined distance.

In the accompanying drawings FIG. 1 is a fragmentary perspective view illustrating the assembly, according to one example of the invention, of an ignition distributor,

FIG. 2 is a view similar to FIG. 1 of a modification,

and

FIG. 3 is a diagrammatic sectional view of the distributor assembled.

Referring to the drawings, the distributor includes an annular base plate 11 including a pair of diametrically opposite tags, (not shown) by means of which the base plate is mounted within the casing of the ignition distributor. The central hole of the plate 11 is extended at right angles to the plane of the plate 1 1 to define a short cylindrical spigot 11a, and upstanding from the periphery of the plate 11 are three deformable tags 12 (only one of which is shown). The tags 12 are integral with the plate 11, and for convenience are equi angularly spaced about the periphery of the plate 11. Each tag 12 includes an arm 13 which, prior to the assembly of the distributor lies in the plane of the remainder of the tags 12. An annular timing plate 14 which will carry the contact breaker assembly of the distributor is engaged with the plate 1 l, the spigot of the plate 1 1 entering the central hole in the plate 14 and serving to locate plate 14 for angular movement relative to the plate 1 about the axis of the spigot. A deforming tool T is engaged with the arms 13 of the tags 12, and the arms 13 are bent to overlie the plate 14. The tags 12 are then deformed so that the arms 13 engage the upper surface of the plate 14, whereupon the deforming tool is removed. The physical properties of the tags 12 are such that the inherent resilience of the tags l2'causes the tags 12 to move in a direction to space the arms 13 from the surface of the plate 14 by a predetermined distance when the deforming tool is removed. Thus, the arms 13 prevent disengagement of the plate 14 from the plate 11 in an axial direction, but provide a minimum clearance which is required to prevent appreciable drag between the plate 11 and the plate 14,

the plate 11. The minimum clearance is equal to the distance through which the arms 13 are moved away from the surface of the plate 14 by the inherent resilience of the tagsl2.

The assembly defined by the plate 11 and the plate 14 is inserted into the casing 21 of an ignition distributor and the assembly is secured to the casing by inserting screws through holes in the lugs on the plate 11, the screws engaging the casing of the distributor. The cam shaft 22 of the distributor extends upwardly through the spigot 11a of the plate 11, and the contact breaker assembly of the distributor is mounted on the surface of the plate 14 remote from the plate 11. A vacuum advance capsule not shown secured to the casing 21 of the ignition distributor is connected to the plate 14 by means of a connecting rod, and the plate 14 is moved relative to the casing of the ignition distributor upon operation of the vacuum capsule, the plate 14 moving about the axis of the spigot of the plate 11. The cam shaft 22 of the distributor is co-axial with the spigot 1 In of the plate 11, and so movement of the timing plate 14 under the action of a vacuum capsule adjusts the ignition timing of the distributor without altering the contact gap as the contact breaker assembly, since the contact breaker assembly is moved in an arc of a circle having its center on the axis of the cam shaft. In use the casing 21 is closed by an insulating cap 23.

In a modification, (FIG. 2) the plate 14 is formed with three equi angularly spaced projections 15 of predetermined height (only one being shown). Prior to deforming the arms 13 the plate 14 is orientated on the plate 11 with respect to the tags 12 so that the projections 15 will be beneath the arms 13. During deforming of the tags 12, the arms 13 engage the free ends of the projections on the plate 14, so that when the deforming tool is removed the tags 12spring back so that the arms 13 are space by a predetermined distance from the free ends of the projections 15. Prior to assembly of the plates 11, 14 in the distributor, the plate 14 is moved angularly with respect to the plate 11 to displace the projections 15 from beneath the arms 13. Thus, the minimum clearance between the arms 13, and the plate 14 is equal to the height of the projections 15 on the plate 14 plus the amount by which the arms 13 spring away from the projections when the deforming tool is removed. In both constructions described above the plate 14 carries a plurality of nylon bearing pads which engage the plate 11, and which minimize drag between the plates 11, 14 during relative movement thereof.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A method of assembling an ignition distributor of the kind specified including the steps of engaging an annular timing plate with an annular base plate so that mating surfaces on the two plates locate the timing plate for angular movement on the base plate, engaging a deforming tool with three resilient ears which are formed on a first plate of the pair of plates defined by the timing plate and the base plate, and deforming the three ears into contact with the surface of the second plate remote from the first plate, said ears being disposed on the first plate in such a manner that any one of the ears is on the opposite side of a diameter of the first plate fromv the remaining ears, and the physical properties of the ears beingsuch that .upon removal of the deforming tool the inherent resilience of the ears causes the ears to flex away from the surface of the second plate through a predetermined distance so that a predetermined clearance exists between the second plate and the ears thereby rendering the first and second plates capable of relative axial movement through said predetermined distance.

2. A method as claimed in claim 1 wherein the ears are deformed into contact with respective projections upstanding from said surface of the second plate, the ears flexing away from said projections through a predetermined distance when said tool is removed, and the second plate, then being rotated relative to the first plate so that the projections are displaced angularly from the ears and the clearance between the second plate and the ears is equal to the height of the projections plus said predetermined distance.

3. A method as claimed in claim 1 wherein said first plate includes a cylindrical spigot which passes through said second plate to mount said second plate for angular movement on the first plate.

4. A method as claimed in claim 2 wherein said first plate includes a cylindrical spigot which passes through said second plate to mount said second plate for angular movement on the first plate. 

1. A method of assembling an ignition distributor of the kind specified including the steps of engaging an annular timing plate with an annular base plate so that mating surfaces on the two plates locate the timing plate for angular movement on the base plate, engaging a deforming tool with three resilient ears which are formed on a first plate of the pair of plates defined by the timing plate and the base plate, and deforming the three ears into contact with the surface of the second plate remote from the first plate, said ears being disposed on the first plate in such a manner that any one of the ears is on the opposite side of a diameter of the first plate from the remaining ears, and the physical properties of the ears being such that upon removal of the deforming tool the inherent resilience of the ears causes the ears to flex away from the surface of the second plate through a predetermined distance so that a predetermined clearance exists between the second plate and the ears thereby rendering the first and second plates capable of relative axial movement through said predetermined distance.
 2. A method as claimed in claim 1 wherein the ears are deformed into contact with respective projections upstanding from said surface of the second plate, the ears flexing away from said projections through a predetermined distance when said tool is removed, and the second plate, then being rotated relative to the first plate so that the projections are displaced angularly from the ears and the clearance between the second plate and the ears is equal to the height of the projections plus said predetermined distance.
 3. A method as claimed in claim 1 wherein said first plate includes a cylindrical spigot which passes through said second plate to mount said second plate for angular movement on the first plate.
 4. A method as claimed in claim 2 wherein said first plate includes a cylindrical spigot which passes through said second plate to mount said second plate for angular movement on the first plate. 